Striking device for a typewriter

ABSTRACT

The typewriter has type bars with key levers and guide and return means for the key levers. The guide and return means are constituted by flexible guide parts arranged in two substantially parallel rows and extending over the whole width of the machine keyboard. The guide parts are fixed by one of their ends on a support rigidly fixed to the frame of the machine, whilst their free outer ends cooperate with the said type levers.

O United States Patent 1 1 1111 3,789,970

Costa Feb. 5, 1974 [54] STRIKING DEVICE FOR A TYPEWRITER 2,971,6252/1961 Rix 197/17 Inventor: Georges Costa Y erdon 3,353,647 11/1967Huge] 197/98 X Switzerland Primary Examiner--Robert E. Bagwlll [73]Asslgnee: Palllard S. A. Vaud, Sa1nte-Cro1x, Assistant E5gminr Rfir-Bidder my 77 Swltzefland Attorney, Agent, or F irm Emory L. Groff;Emory L. 22 Filed: Dec. 1, 1971 [21] Appl. No.: 203,515

[57] ABSTRACT [30] Foreign Applicati P io it D t The typewriter has typebars with key levers and guide Dec. 15 1970 Switzerland 18598/70 andreturn means for the key levers- The guide and turn means areconstituted by flexible guide parts ar- [52] U.S. Cl. 197/17 ranged intwo Substantially parallel rows and extend 51 Int. Cl B4lj 23/08 ingOver Width of the machine keyboard- 58 Field of Search-197/17,9s;235/145, 146 The guide Parts are fixed by one of their ends a1 support rigidly fixed to the frame of the machine, [56] ReferencesCited whilst their free outer ends cooperate with the said UNITED STATESPATENTS type levers 3,633,723 1/1972 Kosters 197/17 4 Claims, 4 DrawingFigures E III III[ PAIENIEDFEB 51914 INVENTOR ATTORNEY STRIKING DEVICEFOR A TYPEWRITER The present invention relates to striking devices fortypewriters.

In striking devices of known types for typewriters, the key levers aregenerally pivoted to the frame and restored by a spring into restingposition. In addition to the pivot, guide means are provided to avoidlateral play of these levers.

It is an object of the present invention to provide a very simple andeconomic method of ensuring at the same time and with minimum of play atthe pivot, the guidance and restoring of the key levers. It enables theproduction of key levers of small inertia with parallel guidance of thekey having little frictional loss.

According to the invention, there is provided a striking device for atypewriter with type bars comprising key levers and guide and returnmeans for the said key levers, characterized in that the said guide andreturn means are constituted by flexible guide parts, arranged in tworows substantially parallel between themselves and extending over thewhole width of the keyboard of the machine, the said guide parts beingfixed, by one of their ends on a support rigidly fixed to the frame ofthe machine, whilst their free ends cooperate with the said key levers.

In order that the invention may be more fully understood, severalembodiments of striking devices according to the invention are describedbelow, purely by way of illustrative but non-limiting example, withreference to the accompanying drawings, in which:

FIG. 1 is a side view of one embodiment of a striking mechanismaccording to the invention;

FIG. 2 is a partial view from below of FIG. 1;

FIG. 3 is a rear view, on a large scale, of a detail of FIG. 1;

FIG. 4 is a side view of a different embodiment.

The device shown comprises key levers 1 each bearing an actuating key 2of the striking mechanism. Each key lever 1 has, at one of its ends, afinger 3 capable of being engaged in a guide slot of a front comb 4. Atits other end, the key lever 1 is guided by two fingers 5 and 6 engagingin guide slots 7, 8. These guide slots constitute a rear comb 9 formingone of the arms of a support 10 in the general shape ofa U rigidly fixedto the frame, not shown, of the machine and arranged in front of thekeyboard. On the other or front arm 11 of the U- support 10 are fixedtwo rows of identical flexible strips l2, 13 substantially parallel toeach other. The upper row 12 is fixed at the point of origin of the arm11 of the U whilst the lower row 13 is fixed to the curved end of thesaid arm. The free ends of the strips of these rows extend to thevicinity of the opposite arm or comb 9 of the U-shaped support 10.

The strips 12 and 13 of each of the two rows of strips are cut out oftwo strips of metal or plastic material and constitute combs fixedrespectively at 14 and at 15 on the U-support 10, by strips 12' and 13'screwed or riveted onto the said support. The free ends of the flexiblestrips 12 and 13 are provided with apertures 16 in which are engaged thefree ends 5 and 6' of the fingers 5 and 6 of the key lever 1.

This arrangement enables very simple assembly of the key levers on theU-support 10 on which the two rows of flexible strips 12 and 13 havebeen previously fixed. It suffices to insert the fingers 5 and 6 of eachkey lever into the slots 7 and 8, the strips 12 and 13 having beenpreviously bent downwardly, then to guide the ends 5 and 6 of thesefingers into the corresponding apertures 16 of the strips 12 and 13. Thefingers 5 and 6 being normally centered in the slots 7 and 8 by theflexible strips, these slots only contribute to the guidance whenabnormal forces are exerted on the keys, which forces are manifested bytwisting of the flexible strips. Under these conditions of normalactuation, frictional forces are therefore very slight.

The striking device also comprises an actuating lever 17 of archedshape, pivoting around a rod 18. This lever is restored to a restposition by a spring 19 against the stop 20 on which it is supported byits heel 21. The stop 20 is fixed to an extension 22 of the front comb4. The actuating lever 17 has, close to its pivoting rod 18, a hole 23for a pin 24 rigidly fixed to an arm 25 mounted pivotably at 26. Thisarm 25 places in motion, through a pull rod, not shown, a type bar, alsonot shown, for effecting the impression of the type element concerned.

In the neighbourhood of the end of the actuating lever 17 opposite thepivoting pin 18 is mounted a catch 27 pivoting around a screw 28, ofwhich the nose 29 is capable of cooperating with the teeth 30 of asplined actuating shaft 31 for continuous rotation in the direction ofthe arrow B. The catch 27 is held in the rest position, shown in FIG. 1,by means of a jump spring 32 engaging, on one hand, in a slot providedon the catch 27 and, on the other hand, in a groove provided at the endof the arched lever 17. In this rest position, the catch 27 is supportedon the arched lever 17 by means of a stop 33 rigidly fixed to thiscatch.

On the key lever l is mounted a catch 34 pivoting around a pin 35 and ofwhich the nose 36 is capable of cooperating with a heel 37 of the catch27, so as to cause the latter to pivot. The catch 34 is held in restposition by a spring 38 fixed on the key lever 1. In this rest position,the catch 34 comes into abutment against a heel 39 possessed by the saidkey lever.

The operation of the mechanism is as follows:

Pressure exerted on a key 2 of the keyboard displaces vertically, in thedirection of the arrow A, the key lever 1 against the restoring actionof the parallel flexible strips 12 and 13. The movement of the key leverl is limited by the abutment of its finger 3 against the bottom of theslot 4. The flexible strips 12 and 13 bend and then take up thepositions indicated in dashed line in FIG. 1. On the downward movementof the lever l, the catch 34 displaces the catch 27 to bring its nose 29into the path of the teeth 30 of the actuating shaft 31. A tooth 30 thenpushes the catch 27 which drives the arched lever 17 in the direction ofthe arrow C in opposition to the spring 19.

The movement of the lever 17 is transmitted to the arm 25 through thepin 24. The edge of the hole 23 forms a ramp enabling progressiveacceleration of the arm 25 and of the type bar. At the end of the strokeof the lever 17, the catch 27 comes into abutment against a pin 151,which restores the catch into its initial position, against the effectof the jump spring 32. The lever 17 is then restored into restingposition by the spring 19.

FIG. 4 illustrates another embodiment of the striking device, in whichthe return and guide means of each key lever 1 are constituted by aguide part 40, made of synthetic material, having two parallel flexiblearms 41 and 42 connected by a web or median portion 43.

Each guide part 40 is engaged by its median portion 43 in a slot 51 of arear comb 48 fixed to the frame of the machine, not shown. In addition,the guide part 40 is mounted on two transverse parallel fixed pins 44and 45, respectively engaged in two holes of the median portion 43 atthe height of the arms 41 and 42. The two parallel pins 44 and 45 arefixed to the rear comb 48 by flanges, not shown, distributed over thelength of the comb. On the other hand, the guide part 40 is hinged atthe end of its flexible arms 41 and 42 through two pins 46 and 47'engaging in two holes provided respectively on two lugs 46, 47 withwhich the key lever 1' is provided and which engage in two guide slots49, 50 of a rear comb 48.

In the resting position of each key, the guide part 40 which isassociated with it is in a state of tension sufficient for the flexiblearms 41 and 42 to exert on the key lever l a return force sufficient tohold this lever in abutment by its lug 46 against the bottom of theguide slot 49.

The other guide parts 40 corresponding to the other key levers, notshown, are mounted side by side, each in a slot of the rear comb 48, ontwo fixed transverse pins 44 and 45, which are arranged parallel to thecylinder, not shown, of the machine. In this embodiment, the drivemechanism of the type bar is identical with that of FIG. 1.

It suffices to mount firstly on each type lever l a guide part 40 byintroducing the two pins 46 and 47 into the corresponding holes of thelugs 46 and 47. This assembly is then placed in the slots 49, 50 and 51of the rear comb 48, the width of the slots 49 and 50 no longerpermitting the pins 46' and 47' to be disengaged from the lugs 46 and47. When all the key levers are in position, the two transverse pins 44and 45 are threaded into each of the holes provided on the medianportion 43 of the parts 40. The shape of these parts 40 is such that,when they are held in place by the pins 44 and 45, their arms 41 and 42are elastically deformed and exert the role of a return spring for thekey levers whilst insuring guidance of the said levers by theparallelogram arrangement.

I claim:

1. A striking device for a typewriter provided with a plurality oftypebars, a keyboard including a plurality of key levers attached toflexible means for the guiding and recall of each said key lever, arigid U-shaped support fixed relative to the frame of the typewriter andprovided with a front arm and a rear arm, said flexible means comprisingat least two rows of substantially parallel resilient strips, saidstrips each having one end fixedly attached to said support adjacentsaid front sup port arm, said strips each having an opposite free endattached to each said key lever adjacent said rear support arm, saidrear support arm including guide slots engageable by each said key leveradjacent the point of attachment between said strip free ends and saidkey levers, and said strips forming each said row are cut from a singlepiece of resilient material.

2. A device according to claim 1, wherein, each set key lever includesfingers disposed within said guide slots, said strip free ends eachprovided with an aperture, and the end portion of each said finger isdisposed within one said strip aperture to provide said point ofattachment between said strips and key levers, whereby said stripsmaintain the positioning of said key levers within said guide slots.

3. A striking device for a typewriter with a plurality of type bars, akeyboard including a plurality of adjacent key levers attached toflexible means for the guiding and recall of each said key lever, arigid rear comb support member affixed to the frame of the typewriterand provided with guide slots engageable by each said key lever adjacentthe point of attachment between said flexible means and said key levers,said flexible means comprising for each said key lever a U-shapedresilient member including a pair of parallel arms each having a freeend attached to each said key lever adjacent each said guide slot, eachsaid pair of parallel arms connected by a web portion fixed relative tothe frame of the typewriter, a pair of lugs on each said key leverpivotably connected to a respective pair of said parallel arm free ends,and said lugs are each disposed in one said slot of said rear combsupport member, whereby, said parallel arms maintain the positioning ofsaid key levers within said guide slots.

4. A device according to claim 3 including, a pair of parallel pinsaffixed to the frame of the typewriter and extending the entire lateralextent of the plurality of key levers, and the ends of each of said webportions connecting said pairs of parallel arms are mounted on said pairof parallel pins.

1. A striking device for a typewriter provided with a plurality oftypebars, a keyboard including a plurality of key levers attached toflexible means for the guiding and recall of each said key lever, arigid U-shaped support fixed relative to the frame of the typewriter andprovided with a front arm and a rear arm, said flexible means comprisingat least two rows of substantially parallel resilient strips, saidstrips each having one end fixedly attached to said support adjacentsaid front support arm, said strips each having an opposite free endattached to each said key lever adjacent said rear support arm, saidrear support arm including guide slots engageable by each said key leveradjacent the point of attachment between said strip free ends and saidkey levers, and said strips forming each said row are cut from a singlepiece of resilient material.
 2. A device according to claim 1, wherein,each set key lever includes fingers disposed within said guide slots,said strip free ends each provided with an aperture, and the end portionof each said finger is disposed within one said strip aperture toprovide said point of attachment between said strips and key levers,whereby said strips maintain the positioning of said key levers withinsaid guide slots.
 3. A striking device for a typewriter with a pluralityof type bars, a keyboard including a plurality of adjacent key leversattached to flexible means for the guiding and recall of each said keylever, a rigid rear comb support member affixed to the frame of thetypewriter and provided with guide slots engageable by each said keylever adjacent the point of attachment between said flexible means andsaid key levers, said flexible means comprising for each said key levera U-shaped resilient member including a pair of parallel arms eachhaving a free end attached to each said key lever adjacent each saidguide slot, each said pair of parallel arms connEcted by a web portionfixed relative to the frame of the typewriter, a pair of lugs on eachsaid key lever pivotably connected to a respective pair of said parallelarm free ends, and said lugs are each disposed in one said slot of saidrear comb support member, whereby, said parallel arms maintain thepositioning of said key levers within said guide slots.
 4. A deviceaccording to claim 3 including, a pair of parallel pins affixed to theframe of the typewriter and extending the entire lateral extent of theplurality of key levers, and the ends of each of said web portionsconnecting said pairs of parallel arms are mounted on said pair ofparallel pins.